Improvement in locks



UNITED STATES PATENT OFFICE.

HENRY H. ELWELL, OF SOUTH NORWALK, CONNECTICUT, ASSIGNOR TO THE NORWALK LOCK COMPANY.

IMPROVEMENT IN LOCKS.

Specification forming part of Letters Patent No. 4 [,573, dated February 9, 1864.

T 0 all whom it may concern.:

Be it known that I, HENRY H. ELWELL, of South Norwalk, in the county of Fairfield and State of Connecticut, have invented a new and useful Improvement in Locks; and I do hereby declare that the following is a full,

clear, and exact description of the same, reference being had to the accompanying drawings, making apart ot' this specication, in which- Figure 1 is an internal view of a lock constructed according to my invention; Fig. 2, a sketch of a lock constructed in the ordinary way, in order to show the difference between it and my invention.

This invention relates to an improvement in the means employed for actuating the latchbolt, whereby a better leveragepower is obtained than by the old plan or arrangement, and a more uniform spring allowed to be used and a very desirable lock obtained, as hereinafter fully set forth.

To enable those skilled in the art to fully understand and construct my invention, I will proceed to describe it.

A, Fig. 1, represents a lock-case of rectangular form; B, tlielockb0lt, and C the latch bolt. D is the hub through which the arbor of the knobs passes. This hub is provided with two projections, a a, as usual, and E is a lever formed with two'arms, b b', which are' nearly at right angles with each other, and also provided with a short arm or projection, c, which is nearly in line with the arm b. The fulcrum r1 of the lever E is at the angle ofthe two arms b b', and the armb has a semicircular recess in it for the hub D to fit into. The arm b', it will be seen by referring to Fig. 1, extends down between the hub D and the end plate, e, of the lock, and the latch-bolt C is connected to the lower end of said arm b.

F is a U-shaped spring, one end of which bears against the short arm or projection c of the lever E, and the other end against a stump or projection, d, in the case A. This spring F has a tendency to keep the latch-bolt C thrown outward from the case A as far as it is designed to extend outward, as will be seen by referring to Fig. 1.

From the above description it will be seen that a good leverage-power of the hub D on the arm b of the lever E is obtained, and con` sequently said latch-bolt may be easily operated, and by the arrangement of the lever E, as shown, a Ushaped spring may be used ywhich has about an equal action throughout,

or much more so than the ordinary flat spring e, as shown in Fig. 2. The ordinary lever, G, (shown in Fig. 2,) is placed between the hub H and the back edge of the lock-case, and but a short leveragepower of the hub H on the lever G is obtained. This difficulty cannot be obviated with this arrangement. The hub H cannot be placed lower down to increase the leverage-power, as that would bring the knob too close to the key of the lock, so that in grasping the knob to turn it the hand would come in contact with the key. lThis would be the casein small locks, which are mostly used.

These two advantages above specied constitute a great improvement in the ordinary cheap lock. A good spring is highly importint. It prevents unnecessary wear and insures a perfect operation of the latchbolt, while the increased leverage admits of the latch-bolt being readily operated or without any undue effort. The improvement at the same time is not attended with any additional expense in the manufacture.

The advantage ot' my improvement in the way of increased leverage is shown by the dotted lines ax, in Figs. 1 and 2.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The peculiarlyvshaped lever E, pivoted to the lock-case, as described, in combination with the hub D, spring F, and latch-bolt C.

, HENRY H. ELWELL.

Vitnesses Tues. L. J DoUGLAs, GEO. W. REED. 

